Then I wasn't remembering wrong and adding the Z in error after all.
All I knew for certain is I ordered the SunPass pro because a) it's portable and can move from vehicle to vehicle and b) it's good in GA and FL (the only 2 states I go to with tolls) and c) there's no added costs to have it.
And I noticed if we ever did drive around the Eastern half of the US, it works in most all locations with tolls.
I avoided Peachpass because it's sticker only, can't move from car to car. Even though it too is valid in FL